title: PR3-ANCA: a promising biomarker for ulcerative colitis with extensive disease.
abstract: BACKGROUND
  We determined if PR3-ANCA is a biomarker that differentiates ulcerative colitis (UC) from Crohn's disease (CrD).
  
  
  METHODS
  A total of 946 sera were tested, including 86 granulomatosis with polyangiitis (GPA) and 491 inflammatory bowel disease (IBD) patients (283 UC and 208 CrD), 264 pathological controls (various diseases) and 105 healthy individuals. All samples were tested for PR3-ANCA by ELISA (QUANTA Flash Lite®, INOVA Diagnostics) and chemiluminescent immunoassays (CIA QUANTA Flash PR3). Conventional anti-neutrophil cytoplasmic antibody (ANCA) indirect immunofluorescence assays (IIF) was performed with NOVA Lite™ (INOVA Diagnostics).
  
  
  RESULTS
  PR3-ANCA by CIA were detected in 31.1% UC vs. 1.9% CrD sera (p=2.2E-16), and by ELISA in 6% UC and 0% CrD (p=0.0003). In GPA patients, PR3-ANCA were detected in 75.6% by CIA and 61.6% by ELISA (p<0.05). PR3-ANCA by CIA were more prevalent in E3-UC compared to E1/2-UC (p<0.05), and in patients with shorter disease duration (p<0.0001). PR3-ANCA showed similar sensitivity, but significantly higher specificity (p<0.05), compared to atypical pANCA by IIF.
  
  
  CONCLUSIONS
  The novel PR3 CIA may prove helpful in the differentiation of CrD from UC, as well as in the identification of UC patients with more extensive disease.
authors.affiliation: INOVA Diagnostics, Inc., San Diego, CA, United States. Electronic address: mmahler@inovadx.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Mahler
authors.forename: Dimitrios P
authors.initials: DP
authors.lastname: Bogdanos
authors.forename: Polychronis
authors.initials: P
authors.lastname: Pavlidis
authors.forename: Marvin J
authors.initials: MJ
authors.lastname: Fritzler
authors.forename: Elena
authors.initials: E
authors.lastname: Csernok
authors.forename: Jan
authors.initials: J
authors.lastname: Damoiseaux
authors.forename: Chelsea
authors.initials: C
authors.lastname: Bentow
authors.forename: Zakera
authors.initials: Z
authors.lastname: Shums
authors.forename: Alastair
authors.initials: A
authors.lastname: Forbes
authors.forename: Gary L
authors.initials: GL
authors.lastname: Norman
mesh_terms: D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D003093:Colitis, Ulcerative / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D003424:Crohn Disease / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012720:Severity of Illness Index
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D015415:Biomarkers
keywords: ASCA; Autoimmune disease; CIA; CU; CrD; Crohn's disease; GPA; IBD; IIF; Inflammatory bowel disease; LIA; PR3-ANCA; UC; Ulcerative colitis; WG; Wegener's granulomatosis; anti-Saccharomyces cerevisiae antibody; cANCA; calculated units; chemiluminescence assay; cytoplasmic anti-neutrophil cytoplasmic antibodies; granulomatosis with polyangiitis; indirect immunofluorescence assay; inflammatory bowel disease; line immunoassay; pANCA; perinuclear anti-neutrophil cytoplasmic antibodies; ulcerative colitis